<?php $q = explode(" ", trim(fgets(STDIN))); $ptn = array(); $ptn[0] = array(-2, -1); $ptn[1] = array(-2, 1); $ptn[2] = array(-1, -2); $ptn[3] = array(-1, 2); $ptn[4] = array(1, -2); $ptn[5] = array(1, 2); $ptn[6] = array(2, -1); $ptn[7] = array(2, 1); if ($q[0]==0 && $q[1]==0){ //動かず終了 echo "YES" . PHP_EOL; }else if ($q[0] <= 6 && $q[0] >= -6 && $q[1] <= 6 && $q[1] >= -6){ //6 >= N >= -6のとき $tmp1 = array(); for ($p1=0; $p1<count($ptn); $p1++){ $tmp1[0] = $ptn[$p1][0]; $tmp1[1] = $ptn[$p1][1]; if ($tmp1[0]==$q[0] && $tmp1[1]==$q[1]){ echo "YES" . PHP_EOL; exit; } $tmp2 = array(); for ($p2=0; $p2<count($ptn); $p2++){ $tmp2[0] = $tmp1[0] + $ptn[$p2][0]; $tmp2[1] = $tmp1[1] + $ptn[$p2][1]; if ($tmp2[0]==$q[0] && $tmp2[1]==$q[1]){ echo "YES" . PHP_EOL; exit; } $tmp3 = array(); for ($p3=0; $p3<count($ptn); $p3++){ $tmp3[0] = $tmp2[0] + $ptn[$p3][0]; $tmp3[1] = $tmp2[1] + $ptn[$p3][1]; if ($tmp3[0]==$q[0] && $tmp3[1]==$q[1]){ echo "YES" . PHP_EOL; exit; } } } } //3回やってダメ echo "NO" . PHP_EOL; }else{ //チェック前から外れ echo "NO" . PHP_EOL; }